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Foundations of Physics

, Volume 43, Issue 1, pp 101–114 | Cite as

What We Don’t Know About Time

  • Vijay BalasubramanianEmail author
Article

Abstract

String theory has transformed our understanding of geometry, topology and space-time. Thus, for this special issue of Foundations of Physics commemorating “Forty Years of String Theory”, it seems appropriate to step back and ask what we do not understand. As I will discuss, time remains the least understood concept in physical theory. While we have made significant progress in understanding space, our understanding of time has not progressed much beyond the level of a century ago when Einstein introduced the idea of space-time as a combined entity. Thus, I will raise a series of open questions about time, and will review some of the progress that has been made as a roadmap for the future.

Keywords

String theory Time 

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© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  1. 1.David Rittenhouse LaboratoriesUniversity of PennsylvaniaPhiladelphiaUSA

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